⌃⌥⌘V does nothing

Another app holds the keyboard

While an app has Secure Keyboard Entry on, macOS sends no shortcuts to other apps, so ⌃⌥⌘V can’t reach Carriel. Terminal has it in its menu (Terminal › Secure Keyboard Entry), and some apps turn it on while a password field is focused.

Click the pouch in the menu bar: the footer of the panel names the app, such as “Secure Keyboard Entry on in Terminal”. Turn it off in that app, or click away from its password field, and ⌃⌥⌘V works again.

Another app uses ⌃⌥⌘V

If another app claimed the same shortcut first, pick a different one for Carriel in Settings › Keyboard. Include ⌘ or ⌃ in it, so it can’t be typed by accident in a text field.

Carriel isn’t running

If the pouch isn’t in the menu bar, open Carriel from the Applications folder. To have it start with your Mac, turn on opening at login in Settings › General. On a MacBook with a notch, a crowded menu bar can hide the pouch behind the camera: quit a menu bar app or two to see it.

The way that always works

Clicking the pouch in the menu bar always opens the panel, and dropping a file on the pouch always opens the card. Choose Tuck In… from the pouch’s menu (Control-click it) to open an empty card without the shortcut.